<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
  
</body>
<script>
    var cartGoods = [
        {
            goodsname: '小米10',
            price: 5000,
            isChecked: true,//代表是否选中了  
        },
        {
            goodsname: '苹果10',
            price: 3000,
            isChecked: true,//代表是否选中了  
        }
    ]
    //every 的值 全部返回true则整个放回成立true 其中有一个是false则返回false  
    let newChecked = cartGoods.every(function (val) {
        return val.isChecked
    })
    if (newChecked) {
        console.log("全选")
    } else {
        console.log("没有全选")
    } 
</script>

</html>